U.S. patent number 6,658,593 [Application Number 09/639,093] was granted by the patent office on 2003-12-02 for recording medium for storing start position information for each zone and method of managing data using the information.
This patent grant is currently assigned to Samsung Electronics Co, Ltd.. Invention is credited to Jung-wan Ko.
United States Patent |
6,658,593 |
Ko |
December 2, 2003 |
Recording medium for storing start position information for each
zone and method of managing data using the information
Abstract
A recording medium for storing start position information for
each zone and a method of managing data using the information. In a
disc having a plurality of zones which form a group, and a spare
area which is allocated at the start portion or the end portion of
the group for replacing defects, when start logical sector numbers
of each zone are changed by slipping replacement during
initialization or reinitialization, the information is stored in
the defect management area to thereby increase the compatibility of
the medium. In particular, by the method of managing data using
information stored in a defect management area, generation of
errors is prevented in reading or writing due to the change of a
physical position of a real-recorded file which are caused by wrong
calculation of the start logical sector numbers for each zone.
Inventors: |
Ko; Jung-wan (Yongin,
KR) |
Assignee: |
Samsung Electronics Co, Ltd.
(Suwon, KR)
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Family
ID: |
19568332 |
Appl.
No.: |
09/639,093 |
Filed: |
August 16, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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474748 |
Dec 29, 1999 |
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Foreign Application Priority Data
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Dec 30, 1998 [KR] |
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98-61603 |
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Current U.S.
Class: |
714/5.11;
G9B/20.059; G9B/20.028; 360/48; 360/72.1; 711/112; 360/53 |
Current CPC
Class: |
G11B
20/1883 (20130101); G11B 20/1217 (20130101); G11B
15/52 (20130101); G11B 20/1258 (20130101); G11B
2020/1245 (20130101); G11B 2220/20 (20130101); G11B
2020/1277 (20130101); G11B 2220/2537 (20130101); G11B
2220/2562 (20130101); G11B 2220/2575 (20130101); G11B
2020/1232 (20130101); G11B 2020/1893 (20130101); G11B
2020/1244 (20130101) |
Current International
Class: |
G11B
20/18 (20060101); G11B 20/12 (20060101); G06F
011/00 () |
Field of
Search: |
;714/8,5,42
;360/48,53,75,60,72.1 ;711/200,202,112 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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350 920 |
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Jan 1990 |
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EP |
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357 049 |
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Mar 1990 |
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EP |
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541 219 |
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May 1993 |
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EP |
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5-217298 |
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Aug 1993 |
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JP |
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8-129835 |
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May 1996 |
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JP |
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Other References
US. patent application Ser. No. 09/474,748, Ko, filed Dec. 29,
1999. .
U.S. patent application Ser. No. 09/639,094, Ko, filed Aug. 16,
2000..
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Primary Examiner: Beausoliel; Robert
Assistant Examiner: Wilson; Yolanda L.
Attorney, Agent or Firm: Staas & Halsey LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of application Ser. No.
09/474,748, filed Dec. 29, 1999, now pending.
This application claims the benefit of Korean Application No.
98-61603, filed Dec. 30, 1998, in the Korean Patent Office, the
disclosure of which is incorporated herein by reference.
Claims
What is claimed is:
1. A method of managing data for a reproducing and/or recording
apparatus in which a plurality of zones form a group to manage
defects of a recording medium, a spare area for replacing defects
for the group is allocated on the recording medium, and start
position information for each zone is stored in a predetermined
area of the recording medium, the method comprising: reading the
start position information for each zone; accessing the data based
upon the read start position information; and reproducing the
accessed data, wherein the start position information for a
corresponding one of the zones is determined based upon a number of
the defects generated from a start of the group up to a preceding
zone.
2. The method of claim 1, further comprising storing the start
position information for each zone in a disc definition structure
area of a defect management area which forms the predetermined
area.
3. The method of claim 1, further comprising allocating n bytes to
the start position information for each zone, where n is an
integer, and the start position information includes a start
logical sector number.
4. The method of claim 1, further comprising allocating the spare
area at a start portion and/or an end portion of the group.
5. The method of claim 1, further comprising determining the start
position information of each zone so as not to misalign a start
position of an error correction block at a boundary between each
zone due to a defective sector of the recording medium.
6. A method of managing data for a disc recording and/or
reproducing apparatus in which a plurality of zones form a group to
manage defects of a disc, a spare area for replacing defects of the
group is allocated on the disc, the start position information for
each zone is stored in a predetermined area of the disc, and a
primary defect list is stored on the disc, the method comprising:
reading the stored start position information for each zone;
calculating a second start position information for each zone based
upon primary defect list information; and performing reading and
writing of the data when the stored start position information is
identical to the second start position information.
7. The method of claim 6, further comprising reading the data based
upon the stored start position information when the start position
information is not identical to the second start position
information.
8. The method of claim 6, further comprising informing a user that
the disc has an error when the stored start position information is
not identical to the second start position information.
9. The method of claim 8, further comprising preventing recording
of new data on the disc when the start position information is not
identical to the second start position information.
10. The method of claim 6, further comprising storing the start
position information for each zone in a disc definition structure
zone of a defect management area which forms the predetermined
area, after slipping replacement upon an initialization or
reinitialization of the disc.
11. The method of claim 6, further comprising allocating n bytes to
the start position information for each zone, where n is an
integer, and the start position information includes a start
logical sector number.
12. The method of claim 6, further comprising allocating the spare
area at a start portion and/or an end portion of the group.
13. The method of claim 6, further comprising determining the start
position information for a corresponding one of the zones based
upon a number of defects generated from a start of the group up to
a preceding zone.
14. The method of claim 13, further comprising determining the
start position information for each zone so as not to misalign a
start position of an error correction block at a boundary between
each zone due to a defective sector of the disc.
15. The method of claim 6, further comprising preventing recording
of new data on the disc when the start position information is not
identical to the second start position information.
16. A method of managing data, for a recording and/or reproducing
apparatus in which a plurality of zones form a group, to manage
defects of a recording medium, a spare area for replacing defects
of the group being allocated on the recording medium, a start
position information for each zone being stored in a predetermined
area of the recording medium, and a primary defect list being
stored on the recording medium, the method comprising: reading the
stored start position information for each zone; calculating a
second start position information for each zone based upon primary
defect list information; and preventing recording of new data on
the recording medium when the stored start position information is
not identical to the second start position information.
17. The method of claim 16, further comprising only enabling a
reading of the data from the disc, based upon the stored start
position, when the stored start position information is not
identical to the second start position information.
18. The method of claim 16, wherein the start position information
for a corresponding one of the zones is determined with reference
to a number of defects generated from a start of the group up to a
preceding zone.
19. The method of claim 16, wherein the spare area is at a start
portion and/or an end portion of the group.
20. A method of managing data for a reproducing apparatus which
reproduces user data stored on a disc, the disc having a plurality
of zones forming a group, each zone having a user data area to
store the user data, and a predetermined area to store start
position information for each zone, the method comprising: reading
the start position information for each zone; and accessing the
user data based upon the read start position information, and not
based on a calculation of the start position from a primary defect
list, wherein the primary defect list includes position information
of defective sectors of the disc and the start position information
for a corresponding one of the zones is determined based upon a
number of defects generated from a start of the group up to a
preceding zone.
21. The method of claim 20, further comprising storing the start
position information for each zone in a disc definition structure
area of a defect management area which forms the predetermined
area, after a slipping replacement upon an initialization or
reinitialization of the disc.
22. The method of claim 20, further comprising allocating n bytes
to the start position information for each zone, where n is an
integer, and the start position information includes a start
logical sector number.
23. The method of claim 20, further comprising allocating the group
to include a spare area at a start portion and/or an end portion of
the group.
24. The method of claim 20, further comprising determining the
start position information of each zone so as not to misalign a
start position of an error correction block at a boundary between
each zone due to a defective sector of the disc.
25. A method of managing data for a recording and/or reproducing
apparatus which records and/or reproduces user data, the disc
having a plurality of zones that form a group, each zone having a
user data area to store the user data, and having a predetermined
area to store start position information for each zone, the method
comprising: reading the stored start position information for each
zone; calculating a second start position information for each zone
based upon a primary defect list information; and performing
reproducing from and/or recording to the disc the user data when
the stored start position information is identical to the
calculated second start position information.
26. The method of claim 25, further comprising reproducing the user
data based upon the stored start position information when the
start position information is not identical to the calculated
second start position information.
27. The method of claim 25, further comprising informing a user
that the disc has an error when the stored start position
information is not identical to the calculated second start
position information.
28. The method of claim 25, further comprising storing start
position information for each zone in a disc definition structure
zone of a defect management area which forms the predetermined
area, after slipping replacement upon an initialization or
reinitialization of the disc.
29. The method of claim 25, further comprising allocating n bytes
to the start position information for each zone, where n is an
integer, and the start position information includes a start
logical sector number.
30. The method of claim 25, further comprising allocating a spare
area at a start portion and/or an end portion of the group.
31. The method of claim 25, further comprising determining the
start position information for a corresponding one of the zones
based upon a number of defects generated from a start of the group
up to a preceding zone.
32. The method of claim 31, further comprising determining the
start position information for each zone so as not to misalign a
start position of an error correction block at a boundary between
each zone due to a defective sector of the disc.
33. The method of claim 25, further comprising preventing recording
of user data on the disc when the start position information is not
identical to the calculated second start position information.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of optical recording
media, and more particularly, to a disc for storing information of
start positions for each zone after initialization or
reinitialization of the recording medium, which has a spare area
for defect management of a group formed of a plurality of zones,
and to a method of managing data using the information.
2. Description of the Related Art
A disc is divided into zones so that inexactness of recording due
to a change in speed of a spindle and deterioration of a search
speed, which occur in a constant linear velocity (CLV) method are
suppressed, and a zoned constant linear velocity (ZCLV) method is
used to obtain a higher recording density than that obtained by a
constant angular velocity (CAV) method.
A recordable and/or rewritable disc managed by a predetermined
method of managing defects may have a defective area, which can be
detected through a certification process, when the disc is
initialized. In order to manage the defects, physical sector
numbers for indicating physical position on the disc and logical
sector numbers for recording and managing a file by a file system,
are separately managed. Logical sector numbers are sequentially
given to record and reproduce a file by a file system, in areas
other than areas which are for recording a file, such as a lead-in
area or a guard area for adjusting the change of speed at a
boundary between zones, and an area where defects are generated. A
file is recorded on a disc and reproduced from the disc using
logical sector numbers according to the file system, and a
recording and/or reproducing apparatus receives a logical sector
number from the file system as a position to be recorded and/or
reproduced, and then searches for a physical sector number
corresponding to the logical sector number to perform recording
and/or reproduction.
When a reproducing apparatus or a recording apparatus makes an
error in calculation of the logical sector number, the file is
recorded in a physically wrong area, so that the file cannot be
read by another reproducing apparatus. Also, the file overlaps with
previous recorded data, so that the previous recorded data is
spoiled.
SUMMARY OF THE INVENTION
solve the above problems, it is an object of the present invention
to provide a recording medium which is divided into a plurality of
zones by a method of controlling the speed for each zone such as a
zoned constant linear velocity or a zoned constant angular
velocity, and information on the start position of each zone is
stored after initialization or reinitialization of the recording
medium which forms a group from a plurality of zones and has a
spare area for defect management.
It is another object of the present invention to provide a method
of managing data on the basis of the start position information of
each zone recorded on the disc, to minimize damage of data due to
errors in calculation of the start logical sector number generated
by recording and/or reproducing apparatuses which are different
from each other and ensure stable recording and/or reproducing of
data.
Additional objects and advantages of the invention will be set
forth in part in the description which follows and, in part, will
be obvious from the description, or may be learned by practice of
the invention.
Accordingly, to achieve the first object of the present invention,
there is provided a recording medium comprised of a plurality of
zones in order to manage defects, wherein the plurality of zones
form a group, and a spare area for replacing defects for the group
is allocated, and start position information for each zone is
stored in a predetermined area.
To achieve the second object of the present invention, there is
provided a method of managing data for a reproducing only apparatus
in which a plurality of zones form a group to manage defects of the
disc, a spare area for replacing defects for the group is
allocated, and start position information for each zone is stored
in a predetermined area, comprising the steps of: reading start
position information, which is stored in the predetermined area,
for each zone; and accessing data on the basis of the read start
position information and reproducing the accessed data.
To further achieve the second object of the present invention,
there is provided a method of managing data for a recording and
reproducing apparatus in which a plurality of zones forms a group
to manage defects of the disc, a spare area for replacing defects
of the group is allocated, and the start position information for
each zone is stored in a predetermined area, comprising the steps
of: reading the start position information for each zone, which is
stored in the defect management area; calculating the start
position information for each zone on the basis of primary defect
list information; and performing reading and writing of data when
the read start position information is identical to the calculated
start position information.
Also, the method further comprises the step of reading the data on
the basis of the start position information stored in the
predetermined area when the read start position information is not
identical to the calculated start position information.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and advantages of the present invention will
become more apparent by describing in detail preferred embodiments
thereof with reference to the attached drawings, in which:
FIG. 1 shows the relationship between a one-dimensional structure
of a disc having a size of the DVD-RAM standard version 1.0 and a
start logical number of each zone;
FIG. 2 shows a change of a start logical sector number of each zone
caused by slipping replacement in the disc, which has a group
formed of a plurality of zones;
FIG. 3 shows a change of the starting position of data which is
recorded by the miscalculated logical sector number in the
structure of the disc of FIG. 2;
FIG. 4 shows an example of the structure of a table which includes
information on the start position for each zone in a defect
management area according to the present invention;
FIG. 5 is a flowchart of a data management method of a reproducing
only apparatus according to an embodiment of the present invention;
and
FIG. 6 is a flowchart of a data management method of a recording
and reproducing apparatus according to an embodiment of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now made in detail to the present preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings, wherein like reference
numerals refer to the like elements throughout. The embodiments are
described below in order to explain the present invention by
referring to the figures.
In order to manage defects on a general recordable and/or
rewritable disc, slipping replacement, for skipping defects without
providing logical sector numbers to the defects, is used for
defects (primary defects) generated upon initialization of the
disc, and linear replacement for replacing error correction code
(ECC) blocks of an erroneous zone with normal blocks in a spare
area, is used for defects (secondary defects) generated during use
of the disc.
That is, slipping replacement is used to minimize a reduction in
the recording or reproduction speed due to defects, in which a
logical sector number is provided to a sector which is determined
to be defective during a certification process for inspecting
defects of a disc when the disc is initialized. Here, the logical
sector number is provided to a sector next to the defective sector,
that is, data is recorded or reproduced by skipping a sector where
a defect is generated during recording or reproduction. Here, an
actual physical sector number is shifted by the sector number
designated by skipping the defective sector. Such a
shifting-backwards phenomenon is solved by using the same number of
sectors in a spare area located at the end portion of a recording
area (a group or a zone) as the number of defects in the recording
area. According to the specifications, the position of a defective
sector replaced by slipping replacement is prescribed to be
recorded in a primary defect list (PDL) in a defect management area
(DMA) on a disc.
Slipping replacement cannot be used for a defect which is generated
while a disc is being used. When a defective portion is disregarded
or skipped, discontinuity is introduced into the logical sector
numbering, which means that slipping replacement violates file
system rules. Thus, linear replacement is used for defects
generated during use of the disc, in which an ECC block including a
defective sector is replaced by an ECC block existing in a spare
area. The location of the defective ECC block replaced by linear
replacement is prescribed to be recorded in a secondary defect list
(SDL) in defect management area on a disc. When linear replacement
is used, logical sector numbering is not interrupted. However, when
there is a defect, the positions of sectors on a disc are
discontinuous, and real data for a defective ECC block exists in a
spare area.
Meanwhile, a digital versatile disc random access memory (DVD-RAM)
according to the DVD-RAM standard version 1.0 includes a plurality
of groups each having a user area and a spare area. That is, FIGS.
1A and 1B one-dimensionally show a logical area and a physical area
on part of a disc, respectively, where each zone of the physical
area includes a guard area, a user area, a spare area, and a guard
area which are sequentially arranged. In FIG. 1A, the letters m,
m+1, n, n+1, p, and p+1 represent the end logical sector number of
a first zone, the start logical sector number of a second zone, the
end logical sector number of the second zone, the start logical
sector number of a zone immediately before the last zone, and the
first logical sector number of the last zone, respectively, when
there are no defects. That is, reference numerals 101, 102, 103,
104 and 105 denote a user area, a spare area, a guard area,
defective sectors and a spare area replaced by slipping
replacement, respectively. The guard area 103 is a buffering area
for preventing driving from becoming unstable due to the
differences in rotation speed between zones, and is allocated at
the start and the end positions of each zone. The spare area 102 of
FIG. 1B indicates a spare area of a predetermined size allocated by
a standard. The spare area 102 is constant in each zone. Also, the
spare area 105 indicates a portion of the spare area 102 which is
already used by slipping replacement due to defective sectors
104.
In a conventional method for managing defects, a group is formed of
one zone, and a spare area is allocated at the end of each group.
Each group is managed as a defect management area. Also, FIG. 1B
shows the shifting-backwards phenomenon in which a logical sector
number is shifted backwards by slipping replacement. However, when
spare areas are arranged in each zone, the shifting phenomenon of a
logical sector number ends at the spare area of the corresponding
zone and the start logical sector number of the next zone is
predetermined without being affected by the number of defects as
shown in FIG. 1A. Thus, the start logical sector numbers of each of
the groups are predetermined by a standard so that when data on the
disc is read, the start logical sector numbers for each group may
not be separately managed to search for the corresponding
group.
However, the start logical sector number of each group is
designated as described above. Thus, when defects in a group are
managed by slipping replacement, slipping replacement must be
performed only within a corresponding group. In order to replace
defects generated in a corresponding group using the slipping
replacement, the number of defective sectors that are slipped must
be less than the number of usable sectors in a spare area of the
corresponding group. Thus, a restriction that a large defect
generated in a group must be processed within the same group limits
the maximum size of a defect that can be replaced by slipping
replacement.
If the size of defects to be replaced by slipping replacement is
greater than the size of a spare area in a corresponding group, a
spare area in another group must be used by linear replacement.
However, when linear replacement is used, defects are managed not
in units of sectors but in units of ECC blocks, that is, in units
of 16 sectors. Thus, a spare area of 16 sectors is required to
process one defective sector, which degrades the efficiency of
defect management. Also, a standard size of a spare area for defect
management is predetermined, so that a spare area of the
predetermined size must also be allocated in applications to which
defect management using linear replacement cannot be applied, such
as real time recording. Therefore, the efficiency of area
utilization of a disc is degraded.
To solve these problems, there is proposed a method of managing
defects in which a group is formed of a plurality of zones and a
spare area is allocated at the start portion of the group and/or
the end thereof.
When a group is formed of a plurality of zones, the start logical
sector number for each zone depends on the number of defects.
Particularly, when a spare area exists at the position in which the
group starts, the slipping replacement must be performed backwards,
to thereby complicate calculation in initialization. Particularly,
slipping replacement causes misalignment of the start sector of an
ECC block at a start position of a zone, so that a fragmented ECC
block is located at the zone boundary. When sectors which cannot
form an ECC block at a boundary between zones are skipped to
prevent the fragmented ECC blocks of each zone, calculation of the
start logical sector number with respect to each zone becomes more
complicated.
That is, FIGS. 2A and 2B show a logical area and a physical area of
a disc, respectively, in which a plurality of zones form a group, a
spare area for slipping replacement is allocated at the group, and
the start logical sector number of each zone is changed. Each zone
includes a guard area, a user area, and a guard area, and a spare
area 204 for a group is allocated at the end portion of the group.
Reference numerals 201, 202 and 203 denote a user area, a guard
area and defective sectors, respectively.
When a zone #0 (first zone) has no defects, the logical sector
number which is allocated as the start logical sector number of a
zone #1 (the second zone) is m+1, and when there are no defects,
the start logical sector number of a third zone is n+1, and when a
defect is generated in each zone during initialization, the start
logical sector number is shifted backwards by an amount equal to
the number of the defective sectors.
That is, as shown in FIG. 2B, when the number of defective sectors
in the zone #0 is i, the logical sector numbers are shifted
backwards by i. If there are no defects, as shown in FIG. 2A, the
final logical sector number allocated to the zone #0 is m, however,
the final logical sector number allocated to the first zone
according to the number i of defective sectors is m-i.
Thus, in the DVD-RAM standard version 1.0, when the size of a user
area allocated to the first zone is m sectors, the start logical
sector number of the zone #1 starts from m+1, but when each zone
has no spare area, the start logical sector number of the next zone
is shifted by i as shown in FIG. 2B so that the start logical
sector number of the zone #1 is m-i+1.
In the next zone (zone #2), when the number of defects generated
from the start of the group to the same zone (zone #2) is j, the
start logical sector number is shifted to n-j+1. At this time, i
and j may further include unused sectors for preventing the start
position of the ECC block from misaligning at each boundary between
each zone due to a defective sector, i.e., for skipping the
remaining sectors which cannot form an ECC block at the end of each
zone. Thus, the start logical sector number for each zone is
shifted backwards by the additional spare area.
Here, the spare area 204 may be allocated at the end portion of a
group or the start portion thereof. When the spare area 204 is
allocated at the start portion of group, reverse slipping
replacement is performed, which complicates calculation of the
start logical sector number for each zone. In reverse slipping
replacement, the slipping replacement is performed in reverse and
the remaining sectors which cannot form an ECC block, which are
generated at a boundary between zones after the slipping
replacement, are reallocated at the final portion of the zone,
which complicates calculation.
Also, when the file system is generally recorded at a portion where
the logical sector number of the disc starts, the spare area is
positioned at the start portion of the group, and the calculation
is wrong, the file system cannot be read due to the forward
shifting of the logical sector number.
Thus, when defects are managed in the group forming a plurality of
zones, the start logical sector number for each zone is changed so
that the recording and/or reproducing apparatus must calculate the
start logical sector number for each zone to perform normally
recording and/or reproduction of data on/from a disc. Meanwhile, in
order to read the disc in a reproducing only apparatus such as
DVD-ROM reproducing apparatus and/or a DVD player, the start
logical sector numbers for each zone of the disc must be read, so
that the size of the firmware of the reproducing apparatus is
increased.
FIGS. 3A and 3B show the case of change of the start logical sector
number of a zone when a complicated start logical sector number is
wrongly calculated in a predetermined portion due to errors in
designing a recording and/or reproducing apparatus or a software
bug of a firmware. When the calculation of the logical start
positions of zones is complicated, and thus calculation of the
start logical sector of zones is wrong in a predetermined portion
due to errors of software of a microcomputer which controls
initialization of the reproducing apparatus, a normal position of
the physical area shown in FIG. 3B corresponding to a position of
the logical area of the file in a zone #K shown in FIG. 3A, which
is 301, may be 302.
As shown in FIG. 3B, a zone 303 where logical sector numbers
overlap, a zone 304 where the logical sector number is wrong, or a
zone 305 where the logical sector number is not designated, may be
generated. In particular, zones 303 and 305 can be easily found,
but zone 304 cannot be easily found by any corresponding
reproducing apparatus. In the drive system having a wrong
calculation, wrong positions may be recorded or a normally recorded
portion cannot be read due to the wrong calculation of the start
logical sector number.
When the file is abnormally recorded, and a wrong recorded disc is
recorded and/or reproduced wrongly in a normal recording and/or
reproducing apparatus, or a normally recorded disc is managed in a
recording and/or reproducing apparatus in which the start logical
sector number is wrongly calculated, the file may be wrongly read
and written. In particular, when the defect management area is
allocated to the start position of the group, slipping replacement
is performed in reverse so that the first position of the logical
sector number may be wrong, where the file system cannot be
read.
To solve the above problem, when the start logical sector numbers
for each zone are determined after slipping replacement on
initialization or reinitialization, the start logical sector
numbers for each zone are stored in a disc definition structure
(DDS) area of the defect management area. That is, as shown in FIG.
4A, the start logical sector numbers for each zone are recorded in
the DDS area using a recording item of 4 bytes. Here, RBP shows a
relative byte position, and start logical sector numbers for 35
zones from a reserved 256th byte position of the DDS area can be
allocated in unit of 4 bytes, as an example. FIG. 4B denotes the
structure of the DDS where the start logical sector numbers of 4
bytes for each zone are stored, where the start logical sector
numbers are recorded in 24 bits and the remaining bits are
reserved.
When a disc on which the start logical sector numbers for each zone
are recorded is read or written in another recording and/or
reproducing apparatus, the following operations may be
performed.
The reproducing only apparatus requires no calculation of the start
logical sector numbers. This is because the recording and/or
reproducing apparatus records data on the basis of the wrong start
logical sector number even though the start logical sector number
recorded in the DDS area is wrong, and thus the reproducing only
apparatus must read data on the basis of the stored start logical
sector number. Thus, it is most secure to read data with reference
to the start logical sector number recorded in the DDS area without
complicated calculation and regardless of wrong calculation of the
start logical sector number recorded in the DDS area. Thus, the
reproducing apparatus requires no algorithm for calculating the
complicated start logical sector number to thereby simplify the
firmware.
That is, in the reproducing only apparatus, as shown in the
flowchart of FIG. 5, the start logical sector number for each zone
stored in the DDS area is read (S101), and data is accessed based
on the read start logical sector number to be produced (S102).
Meanwhile, when the disc is installed in a recording and
reproducing apparatus, the start logical sector number of the DDS
area is read, but the start logical sector number is calculated on
the basis of PDL information of the defect management area. If the
recorded information is consistent with the information obtained by
calculation, the apparatus performs normal recording and
reproduction, and if not, the apparatus only reads data on the
basis of the start logical sector information recorded on the disc.
This is because the data of the disc is recorded on the basis of
the start logical sector number which is stored in the DDS area for
each zone. Also, it is most secure not to record additional data
until it is determined which information is wrong. Thus,
information must not be recorded on the disc until it is determined
why the start logical sector number of the disc is inconsistent and
a proper action is performed.
That is, in the recording and reproducing apparatus, as shown in
the flowchart of FIG. 6, the start logical sector number for each
zone stored in the DDS area is read (S201), and the start logical
sector number for each zone is calculated on the basis of the PDL
information of the defect management area (S202). Then, it is
determined whether the start logical sector numbers read in step
201 are identical to the start logical sector numbers calculated in
step 202 (S203), and if so, normal data read and write operations
are performed (S204). If not, the fact that the disc has an error
is indicated to a user (S205), data is read on the basis of the
start logical sector number stored in the DDS area (S206), and no
data is recorded on the disc until the error is cleared by a fixing
tool (S207).
As described above, the start logical sector number corresponding
to the start position information for each zone is stored in the
defect management area so that the reproducing only apparatus
requires no algorithm to calculate the complicated start logical
sector number.
Also, when the stored information is inconsistent with the
corresponding calculated start position information for each zone,
damage of data due to errors of calculation of the start logical
sector number generated by recording and reproducing apparatuses
which are different from each other, using the stored start
position information for each zone, is minimized and stability of
the recorded data is increased.
Although a few preferred embodiments of the present invention have
been shown and described, it would be appreciated by those skilled
in the art that changes may be made in this embodiment without
departing from the principles and spirit of the invention, the
scope of which is defined in the claims and their equivalents.
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